Re: [Maria-developers] ab6ef429a84: MDEV-16370 row-based binlog events (updates by primary key) can not be applied multiple times to system versioned tables

Hi Sergei! On Wed, Mar 13, 2019 at 7:16 PM Sergei Golubchik wrote:

Hi, Aleksey!

On Jan 31, Aleksey Midenkov wrote:

...

revision-id: ab6ef429a84 (versioning-1.0.7-2-gab6ef429a84) parent(s): 14c2f90ad08 author: Aleksey Midenkov committer: Aleksey Midenkov timestamp: 2018-11-26 12:46:37 +0300 message:

MDEV-16370 row-based binlog events (updates by primary key) can not be applied multiple times to system versioned tables

Case 2:

* Idempotent BINLOG updates: duplicate key on history row is skipped; * Fix row start and warn when applying BINLOG from the past.

As far as I can see now you cannot just arbitrarily adjust row_start.

Think of it in term or application time period tables, a primary key is (kind of) defined WITHOUT OVERLAPS. There is no explicit constraint, it happens automatically when the history is valid.

Now, here's your test case:

timestamp=100; insert (1,1) -> the table has (1,1,100,MAX); timestamp=300; update to (1,3) -> (1,1,100,300),(1,3,300,MAX); timestamp=200; update to (1,2) -> here the hisory row should've been (1,3,300,200) but you adjust it to get

1,1,100,300 1,3,199,200 1,2,200,MAX

and if you select AS OF 199, you'll get two rows for the pk=1

So, let's

* ignore HA_ERR_FOUND_DUPP_KEY (please check if it's needed for insert or delete too) * add TIMESTAMP=xxx to mysqldumps.

Add SET TIMESTAMP for each versioned record or just single SET TIMESTAMP per dump? I almost made the former when I realized that you could mean the latter.

can vers_insert_history_row see row_start>row_end in a normal use case? no replication or any other way of adjusting the timestamp. equality can surely happen, but greater than ?

I don't know of such cases.

Regards, Sergei Chief Architect MariaDB and security@mariadb.org

-- All the best, Aleksey Midenkov @midenok